There is often the need to transmit confidential information through the mail or other channels such as courier, document exchange, hand delivery etc. For example, banks and other financial institutions often mail out Personal Identification Numbers (PINs) associated with customer's credit or debit cards.
Forms are known which carry such information in a secure manner, ie. the information cannot be viewed without first breaching some form of security associated with the form. An example of such a form is a lottery ticket known as a "scratchy" in which a coating must be scratched away to reveal the underlying information.
Necessarily, these forms for securely carrying information are tamper-evident, ie. the act of breaching the security of the information causes some irreversible indication that a breach of security has occurred.
Most tamper-evident forms are constructed such that further processing of the form, such as coating (eg. "scratchy") or folding and sealing, is required to secure the information after the information has been printed on the form. This is a significant inconvenience and often requires special equipment which is prohibitive to many users.
One known tamper-evident form which does not require further processing after the confidential information has been received involves a two-ply arrangement which is sealed together around its perimeter. With this form, an impact printer strikes the upper surface of the upper ply thereby leaving a "carbon" imprint on the upper surface of the lower ply. To access the information on the lower ply, the two plies must be peeled or torn apart.
Preferred embodiments of the present invention provide a tamper-evident form for securely carrying information in which the information can be printed on the form by passing the form through a conventional printer and in which the printed form does not require further processing to render the information secure.